Reworked a lot of the CMake build
- Python bindings installation outside of `scikit-build-core` is no
longer supported. Avoids dangling files that cannot be removed due to
lacking python package metadata files (`spglib.dist-info`)
- Reworked the detection of when the bundled project needs to be
included:
- Check for Target `Spglib::symspg` (more robust than checking for any
cache variables)
  - Use `find_package` to check for system installed `Spglib`
- Use
[`CMAKE_DISABLE_FIND_PACKAGE_Spglib=ON`](https://cmake.org/cmake/help/latest/variable/CMAKE_DISABLE_FIND_PACKAGE_PackageName.html)
to make sure the bundled version is used
- Use
[`CMAKE_REQUIRE_FIND_PACKAGE_Spglib=ON`](https://cmake.org/cmake/help/latest/variable/CMAKE_REQUIRE_FIND_PACKAGE_PackageName.html)
to make sure a system version is used
- If `find_package` failed (and `CMAKE_REQUIRE_FIND_PACKAGE_Spglib` was
not set), use the bundled sources
- Removed the dynamic loading of the `spglib` C library, `libsymspg`
must be resolved at build time
- Added `INSTALL_RPATH` for the python `_spglib` library pointing to
`$ORIGIN/${CMAKE_INSTALL_LIBDIR}`. *If* you want to use a system
installed library, there *must not* be a `libsysmspg` library there
- Reverted the `cibuildweel` workaround from #507

Depends-on: #458 

Closes #510 Closes #462